In the production of garments in an industrial setting, batches of workpieces, for example cloth blanks, are processed through separate work stations for being formed into finished workpieces such as shirt sleeves. The finished workpieces are then conveyed to another work station, or work stations, for being combined into the finished item of clothing. For example, it is common for the sleeves of a shirt to be produced at a first work station, typically a hemming and seaming machine, with the body of the shirt being bottom hemmed, the neck finished, and a waistband added if necessary at additional work stations, and thereafter the body and the sleeves of the shirt are sewn together at a final work station to form the finished garment.
The production of these garments is typically accomplished in high volume, high speed operations in which consistent size and quality of the finished workpieces are required in order to arrive at consistently sized and finished items of clothing at the end of the fabrication process. One problem in working with textile workpieces, however, is that they tend to have a natural elasticity that is typically exhibited during handling, such that wrinkles or undesired curls or folds may occur in the leading edge, trailing edge, or in the body of the workpiece as it is being processed. If these curls or folds are not removed from the workpiece during fabrication, the finished workpiece may be poorly formed, or formed with defects. In addition, consistency in the sewing, hemming, and folding of the workpieces with their seams and hems aligned, and edges matched for folding is critical to ensure that quality is maintained and that the workpieces are not formed with inconsistencies in appearance and size so as to require resewing or discarding of these workpieces. Maintaining such consistency thus requires a high degree of precision in seaming, hemming, and folding of the workpieces, typically at a reduced production rate.
For example, during the production of shirt sleeves, a workpiece blank having a leading edge, a trailing edge, and a first straight side edge extending between the leading edge and the trailing edge is placed on a hemming machine. Thereafter, a hem is sewn in the first straight side edge of the workpiece as the workpiece is moved, leading edge first, along a conveyor and through a hemming station. To form the finished tubular sleeve, the workpiece then must be folded such that the top portion of the hem is aligned with the bottom portion of the hem, and the leading edge is aligned with the trailing edge, if so desired. In the alternative, the workpiece can be folded to a preset size, with any excess leading or trailing edge material needing to be cut off prior to the two edges being sewn together in a seam.
It is during this folding process that unwanted curls often tend to form in the edges of the sleeve, which can disrupt the seam. Also, it is important for the edges to be properly aligned prior to seaming to avoid waste of material and to ensure consistency of size of the finished sleeves. If the edges are not properly aligned before seaming, the finished sleeves can be formed too small or too large to match the shirt sleeve openings of the shirt bodies. As a result, the sleeve or the material of the shirt bodies about these sleeve openings tends to become bunched or puckered due to the elasticity of the cloth of the sleeve and/or body, which must be stretched to match the sleeve openings for sewing. In addition, most hemming and seaming systems are not able to accommodate a wide range of sizes of sleeves such that variations in sizes of the sleeve blanks require an adjustment or recalibration of the machine to seam and hem different size workpieces.
An example of a conventional cloth folding and sewing device designed to remove the curl formed in the leading edge of the workpiece during the folding process, is disclosed in U.S. Pat. Nos. 5,363,784, and 5,197,722, issued to Adamski, Jr., et al. on Nov. 15, 1994, and Mar. 30, 1993, respectively. In the device of the two Adamski, Jr., et al. patents, a workpiece is moved along a path of travel on a conveyor belt toward a sleeve handling (folding) device. Once in the appropriate position, as determined by a sensor, an elongate sleeve pickup blade is moved upwardly from a position beneath the workpiece and engages the underside of the workpiece to drive a leading edge portion upwardly into a pair of spaced jaws formed as a part of a pickup assembly. Thereafter, the leading edge portion of the workpiece, but not the leading edge itself, is held by the jaws as the remainder of the workpiece continues to move along the path of travel on the conveyor to fold the workpiece. To assist in folding the workpiece, a blower is directed in the direction of the path of travel and against the workpiece. Once the workpiece has been folded to the desired size, the jaws release the leading edge portion of the workpiece, but in doing so a fold or a curl is formed at the leading edge of the workpiece. A downstream air blower is thus required in order to direct a jet of air in the direction opposite the direction of movement of the workpiece and into engagement with the folded or curled upper portion of the workpiece to eliminate this fold or curl, all of which is required due to the fold or curl formed in the workpiece by the device of Adamski, Jr., et al. in the first instance. Thus, in order to perform its folding operation, the device of Adamski, Jr., et al. first creates an unwanted problem condition that it must then solve.
What is needed, therefore, is a method and apparatus which automatically, rapidly, and accurately hems, folds and seams workpieces but will not introduce any unwanted folds, curls, or wrinkles in the workpieces during the folding thereof to ensure high production rates with high quality. What is also needed, but seemingly unavailable in the art, is a device which not only can fold the workpiece, but can fold the workpiece to a desired size, or can consistently fold a workpiece in half, no matter the size of the workpiece and despite variances between workpieces without requiring recalibration of the apparatus to ensure consistency and quality in the production of hemmed/seamed workpieces at improved production rates.